SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc8daffaef4710cfa45ce526fca8d9deed47ce16783c24074ba6bd7d60276343' 
  AND token = 'ewxpWxmiKsErEP5cA6Se/xrcXSmbncqwsX6CVpHz52s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}